Left ventricular assist devices are known in the prior art as evidenced by U.S. Pat. No. 4,143,425, issued Mar. 13, 1979 to Runge. Such prior art devices include means for cyclically compressing a valved shunt connected between the left atrium and descending thoracic aorta. The shunt compression element is driven by a motor powered mechanism which includes a spirally grooved rotor or spinner and an axially movable ring follower connected to the spinner by a groove rider or follower. By this means, rotation of the spinner is converted to linear motion of the ring follower which directly operates the shunt compression element. Such a mechanism, while quite reliable, is subject to some of the inherent drawbacks of any mechanical device including gradual wear and friction which will ultimately limit the life of the mechanism.
The object of this invention is to improve on the known prior art through provision of an electrically activated ferromagnetic/diamagnetic vascular shunt cyclical compression means which can be synchronized with the patient's QRS complex by a power source wholly external to the patient's body. In accordance with the invention, mechanical drives, friction and wear are essentially eliminated along with all of the inherent disadvantages of purely mechanical systems. The invention is highly simplified, precise and reliable in operation. Its advantages should be readily apparent to those skilled in the art.